Piano action



Sept. 22, 1959 F. T. MACHALEK PIANO ACTION Filed Sept. 21, 1956 IN VEN TOR. FERDINAND T MACHALEK PIANO ACTION Ferdinand '1 Machalek, Fort- Wayne, Ind., assignor to Intel-national Telephone and Telegraph Corporation Application September 21, 1956, Serial No. 611,113 13 Claims. (Cl. 84237) This invention relates to a piano action, and more par ticularly to an action especially suited for use in an electronic piano.

In recent years, artisans have been striving to develop an electrical or electronic piano which is capable of producing sounds identical to those of the conventional piano, yet be smaller in size, simpler in design and less costly than the conventional piano. One step toward the achievement of this goal is realized in a simplified and improved design of piano action whichwill be disclosed more fully hereinafter.

It is therefore an object of this invention to provide a piano action which is especially adapted for use in electronic pianos and preserves and improves the structural and operational features of the conventional piano action.

It is another object of this invention to provide a piano action in: which the damper of substantially simplified design may be adjusted precisely by means of a single, separate and simple operation.

It is still another object of this invention to provide a piano action wherein the return spring forces on the key are effectively minimized to the point of being imperceptible to the player.

It isstill a further object of this invention to provide a keyboard comprising an array of piano actions having a damper construction whereby all of the individual dampers may be easily adjusted for achieving simultaneous and uniform damper action upon operation of the Sostenuto, or sustaining, pedal.

In accordance with this invention, there is provided a piano action comprising a string, a key and hammer operatively assembled together for attacking the string, a resilient connection operatively interposed between the key and the hammer and exerting a spring force which opposes operation of the key, a damper normally engaging the string, the key operatively engaging and resting on the damper for holding the latter in engagement with the string, resilient means acting on the damper exerting a spring'force which tends to disengage the damper from the string, the forces of said resilient connection and said resilient means as exerted on the key being in opposition, the force of the resilient connection being dominant, and means for selectively releasing the damper from the string.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawing which is a side elevation of a single piano action of this invention with the framework and certain other parts being shown in cross section.

While the drawing illustrates a piano action for a single musical note, it will be understood that a multiplicity of these actions arranged in side-by-side relation constitute a complete piano keyboard. A keyboard frame, indicated by the reference numeral 1, extends along the ice length ofthe keyboard and provides support for all keys, the keyframe la and? the entire action unit 1b. In. the preferred, form of this invention, this frame is of cast metal construction but of-course may be fabricated of wood 013 01.116]: suitable material. Mounted onthe'upper side of the frame 1, on the usual balance pins 2,is a key 3. On-the rear portion of the frame is attached a rail 4 which pivotally supports at 5a whip 5. A suitable adjusting screw 6 passingthrough the end of thewhip Sis engageable with a pad 7- on the rear of the key 3 so that upward movement of the pad 7. resulting from key operation serves to swing the whip 5 counterclockwise.

On the rear or left-hand end of the whip 5 is mounted a jack 8 having two arms 9 and 10, respectively. 'Interposed betweenthe arm 9 and the whip 5 is a helical compression spring characterized hereinafter as jack'spring 11. The force of this spring 11 tends to swing the jack 8 counterclockwise about its pivot 12. A suitable felt-pad 13 is provided on the lowerextremity on the jack arm 10, as illustrated.

Also attached to the rear portion of the frame-1 is a regulating rail 14 which carries anadjustable, felt-padded button 15 which is en-gageable by the shorter arm 9 of the jack 8.

Pivotally mounted on-the-underside of the rail 4. about a pivot pin 16 is a hammer 17. The forward or lower end of this hammer 17 carries a hammer-felt 18 which in operation strikes or impulses the usual. tensioned string 19 stretched between the-usual hitch pin 20 and the tuning 'pin 21. The construction of this particular hammer 17' is the subject of another application for patent by the inventor herein.

On the rear or butt end 17a of the hammer 17 is an upwardly curved finger or back check 22. As Will be noted upon close examination of the drawings, the lower extremity ofthe jack arm 10 is spaced slightly from the hammer butt which curves downwardly. This feature is important for. the reason that as the key 3 is operated, the whip Sis swung counterclockwise, thereby depressing or forcing downwardly the jack arm 10 until it sharply contacts or impulses the hammer 17 butt; The hammer is thereupon flipped or impulsed upwardly into striking relation with the string 19; however, as the hammer swings upwardly, and the end of jack arm 10 continues its travel downwardly, the jack arm slidesrearwardly and downwardly along the curved portion of the buttuntil theback check 22 is engaged. The moment this occurs, the hammer 1 7 is locked or otherwise held against movement and cannot bounce or oscillate intocontact with the string 19. Thus, by means of the back check 22,- the hammer is prevented from striking the string 19- more than once with each operation of thekey 3.

The regulating button 15 is so adjusted that the jack arm it) properly cooperates with the back check 22 in order to stabilize the operation of the hammer 17.

Also mounted on top of the key frame 1 but directly beneath the key 3 is a damper lever 23 which carries a felt pad 24 on its. left-hand end innormal damping engagementwith the string 19. T his. lever 23 pivotally'contacts a sustaining rod 25wl1ich extends the entirel'ength of the piano keyboard, this-rod serving to operate all of the levers 23 of the key actions.

Positioning of the lever 23 on;the frame 1 is accomplished by means of a pin :26 extending upwardly from the frame through a slot 27 in the leverwhichreceives the eyelet-shaped end. 23 of the pin. A helical compression spring 29' surrounding thepin 26 is interposed-between the key frame and the damper lever 23, tending to swing the latter clockwise. around the sustaining ,rod 25.

aThreadedly received throughthe key 3 isa regulating;

screw 30 which projects into contact-.withafelt pad 31 on the upper side of the lever 23. I This. regulating screw St) is so adjusted as to impart the mass or weight of the key 3 to the damper lever 23 for maintaining the normal damping engagement of the felt 24 with the string 19. The damper spring 23 opposes this gravitational force, but is of insuflicient strength to overcome it.

Considering the entire keyboard as it comprises the key actions as just described, the regulator screws 30 are all adjusted so as to provide identical damping engagement of the various felts 24 with the respective strings 19. The sustaining rod 25 may, as in the usual case, be operated by means of a pedal (not shown) which normally moves the rod downwardly. When this occurs, the damper spring 29 is compressed, with the force thereof providing a pivot point along with the lower end of the regulating screw 30 for lifting the damper felt oif the string 19. In this position, a sustaining tone may be produced when the string 19 is struck.

It should be noted that this invention utilizes two springs 11 and 26 which exert opposing forces on the key 3, the spring 11 tending to depress the rear or left-hand end of the key while the spring 26 tends to lift this end. The spring ill is designed in combination with the other elements of the action to overcome the lifting force of the damper spring 29, whereupon the key 3 normally assumes the illustrated position. When the key is operated in the usual manner, it will pivot about the balance pins 2, lifting the rear end and releasing the damper lever 23. The damper spring 29 immediately lifts the damper lever, thereby preparing the string 19 to be attacked by the hammer. Simultaneously with this operation of the key, the hammer 17 is actuated by means of the jack 8. However, the moment the lower extremity of the jack arm lit contacts the hammer butt and the jack 8 tends to swing clockwise about its pivot 12, the spring 11 will be compressed, thereby exerting a force of reaction which opposes actuation of the key 3. Thus it is seen that with the spring 11 opposing key actuation and spring 29 aiding key actuation, the net spring force exerted on the key 3 is effectively balanced, or, in other words, is rendered imperceptible to the person playing the piano. When a player depresses the key 3, he will therefore feel only the reaction of the key mass and other moving parts in the piano depending upon how slowly or rapidly or to what extent the key is operated.

It will now be appreciated that the piano action of this invention as compared to the conventional piano actions is reduced in size and cost yet is simplified in design. All of the adjustments and parts of the action are readily accessible for tuning and servicing, thereby simplifying maintenance. .The action of the damper lever 23 is rapid and almost instantaneous, this being primarily due to the damper spring 29.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is:

l. A piano mechanism of the character described comprising a key, a string operatively associated with said key, a damping lever selectively engageable with said string, a sustaining member pivotally engaged by said damping lever, said key engaging said lever at a point spaced from the pivotal engagement with said sustaining member, a spring urging said lever out of engagement with said string and into engagement with said key, and means yieldably urging said key against said lever and said lever into engagement with said string.

2. A piano mechanism of the character described comprising a key, a string operatively associated with said key, a damping lever selectively engageable with said string, a sustaining member pivotally engaged by said damping lever, an adjustable control screw mounted on said key and engaging said damping lever whereby the weight of said key may be imparted to said lever for 4 holding the latter in engagement with said string, a support, a spring interposed between said support and said lever exerting a force in opposition to the weight of said key, said spring being of insufiicient strength to overcome the weight of said key which normally holds said lever in engagement with said string.

3. A piano mechanism of the character described comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string and being carried by said support, a resilient connection operatively interposed between said key and said hammer and exerting a force opposing operation of said key, a damper resiliently mounted on said support and normally engaging said string, said key pivotally engaging said damper and holding said damper in engagement with said string, resilient means comprising said resilient mounting interposed between said support and said damper which disengages said damper from said string when said key is disengaged from said damper, the forces of said resilient connection and said resilient means as exerted on said key being in opposition, the force of said resilient connection being dominant, and means for selectively releasing said damper from said string.

4. A piano mechanism of the character described comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string and being carried by said support, a resilient connection operatively interposed between said key and said hammer and exerting a force opposing operation of said key, a damper resiliently mounted on said support and normally engaging said string, said key engaging said damper on the side opposite said string, resilient means interposed between said support and said damper which disengages said damper from said string when said key is disengaged from said damper, the forces of said resilient connection and said resilient means as exerted 011 said hey being in opposition, the force of said resilient connection being dominant, and means for selectively releasing said damper from said string.

5. A piano mechanism of the character described comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string and being carried by said support, a first spring operatively interposed between said key and said hammer and exerting a force opposing operation of said key, a damper resiliently mounted on said support, said key pivotally engaging said damper and forcing the latter into contact with said string, a second spring comprising said resilient mounting interposed between said support and said damper and lifting the damper off the string when the key is disengaged from said damper, said first spring exerting the dominant force, and means for selectively withdrawing said damper from said string.

6. A piano mechanism of the character described comprising a key, a string operatively associated with said key, a damping lever selectively engageable with said string, a sustaining member pivotally engaged by said damping lever, said key engaging said lever at a first point spaced from the pivotal engagement with said sustaining member, a spring urging said lever out of engagement with said string and into engagement with said key, said spring engaging said lever at a second point intermediate said first point and the pivotal engagement with said sustaining member, and means yieldably urging said key against said lever and said lever into engagement with said string.

7. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string, a damping lever movable about a pivot and being selectively engageable with said string, said lever being interposed between said key and string, said key engaging said lever at a point spaced from said pivot and yieldably urging said lever into engagement with said string, a spring bearing against said lever in a direction to disengage said lever from said string when said key is disengaged from said lever, a second spring operatively engageable with said key and forcing the latter into engagement with said lever and in turn forcing said lever into engagement with said string.

8. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string, a damping lever movable about a pivot and being selectively engageable with said string, said lever being interposed between said key and string, said key engaging said lever at a point spaced from said pivot and yieldably urging said lever into engagement with said string, a spring bearing against said lever in a direction to disengage said lever from said string when said key is disengaged from said lever, said spring engaging said lever at a point between said pivot and the point of engagement with said key, a second spring operatively engageable with said key and acting on said key in a direction for forcing the latter into ongagement with said lever and in turn forcing the lever into engagement with said string.

9. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string, a damping lever movable about a pivot and being selectively engageable with said string, said lever being interposed between said key and string, an adjusting member carried by said key and engaging said lever on the side opposite said string at a point spaced from said pivot, a spring bearing against said lever in a direction to disengage said lever from said string when said key is disengaged from said lever, a second spring operatively engageable with said key and acting on said key in a direction for forcing the latter into engagement with said lever and in turn forcing the lever into engagement with said string.

10. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assem bled together for impulsing the string, a damping lever movable about a pivot and selectively engageable with said string, said lever being interposed between said key and string, an adjusting screw mounted in said key and extending into engagement with said lever on the side opposite said string at a point spaced from said pivot, a spring bearing against said lever in a direction to disengage said lever from said string when said key is disengaged from said lever, a second spring operatively engageable with said key and acting on said key in a direction for forcing the latter into engagement with said lever and in turn forcing the lever into engagement with said string.

11. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string, a damping lever interposed between said key and said string, a sustaining bar transversely disposed between said key and string, said lever pivotally engaging said bar and extending into engagement with said string, a spring acting on said lever in a direction to swing said lever out of engagement with said string, said spring exerting sufiicient force to disengage said lever from said string, an adjusting member movably mounted on said key and engaging said lever on the side opposite said string, and means for yieldably urging said key against said lever and said lever against said string in opposition to the force of said spring.

12. A piano mechanism comprising a string, a support for the string, a key and hammer operatively assembled together for impulsing the string, a damping lever interposed between said key and said string, a sustaining bar transversely disposed between said key and string, said lever pivotally engaging said bar and extending into engagement with said string, a spring acting on said lever in a direction to swing said lever out of engagement with said string, said spring exerting sufficient force to disengage said lever from said string, a screw adjustably carried by said key and extending into engagement with the lever on the side opposite said string, and a resilient element operatively acting on said key yieldably urging said key against said lever and said lever against said string in opposition to the force of said spring.

13. The mechanism of claim 12 wherein the spring engages said lever at a point intermediate the pivotal engagement with said bar and the engagement with said screw.

References Cited in the file of this patent UNITED STATES PATENTS 427,667 Bunce et al. May 13, 1890 436,511 Wessell Sept. 16, 1890 FOREIGN PATENTS 3,064 Great Britain 1865 164,349 Germany Oct. 27, 1905 141,594 Sweden Aug. 4, 1953 

